The most reliable manner of tobacco priming is by the hands of skilled labour, however, due to the problems in finding labour force for such a short seasonal occupation, there is a strong demand for tobacco priming apparatus. There have been, however, several draw backs with previously proposed tobacco priming machines such as high field loss, damage to the tobacco leaves in the form of bruising, cuts, tears and damage to the tobacco stalks causing stalk bleeding and consequent damage to the elevated higher quality tobacco leaves. Examples of tobacco priming apparatus are disclosed in U.S. Pat. Nos. 3,466,856 and 3,731,475. Both of these patents disclose priming apparatus using knives to cut the leaf stems in removing the leaves from the plant stalk. There are problems associated with such knife cutting of the leaves in that it is difficult to prevent damage to the tobacco stalk and ensure removal of all leaves at a leaf branching level on the plant stalk.
Another type of tobacco harvesting apparatus is that made by Harrington Manufacturing of Lewiston, N.C. and sold under the trade mark "ROANOKE". That type of harvester uses defoliators to break the leaves from the tobacco stalk, however, the apparatus has several shortcomings, among which it is relatively inflexible for varying field conditions resulting in several difficulties for the operator so that there has been a low acceptance of the harvester. Also associated with that harvester are substantial field losses and damage to the picked tobacco leaves.
With increasing difficulties in finding skilled labour for tobacco priming, it has been found that the quality of tobacco picking by hand has deteriorated to field losses and leaf damage in the range of 10 to 15%. This is an unacceptable loss for most tobacco growers therefore increasing the demand for an efficient tobacco harvester.
The tobacco harvester according to this invention overcomes a number of the above identified problems to provide an apparatus which picks the leaves from the plants and gently handles their transfer to storage bins on the harvester. The apparatus is easy to operate, has a great deal of flexibility in set up for varying field conditions such as row width spacing between plants, level of leaves on the plant to be picked, ambient changes such as dampness, dryness and plant characteristics such as brittleness in the leaf stems. The invention also provides the operator with a positive feed-back on the operation of the harvester to enhance performance.